Statistical interactions of vortices in superconducting films

We consider type-II planar superconductors described by time-dependent nonlinear Schrodinger equation. The vortex core remains in a state which is not coherent with the superconducting condensate. The net deficit of the condensate in the core region is a convergent quantity. Under exchange of a pair of vortices the ground state wave function picks up a Berry phase proportional to the number of bound states inside vortex core.